In recent years, in a plant (a process system) such as a power plant, an oil producing apparatus, an oil refinery, a gas plant, a chemical plant, etc., as a method of efficiently implementing maintenance management activities while ensuring reliability and safety, a risk evaluation technique using RBI (Risk-Based Inspection) has been introduced. In this technique, for each one of a plurality of processes constituting the plant, risk evaluation is made based on frequency of occurrence of trouble (failure, etc.) and importance of the process. For instance, by effecting e.g. maintenance in a concentrated manner on a constituent device constituting the process which is evaluated as having high risk, the process system is maintained and managed in an efficient manner. Such risk evaluation technique is disclosed in Japanese Unexamined Patent Application Publication No. 2013-088828 and Japanese Unexamined Patent Application Publication No. 2010-073121, for instance.
Aside from the above, though not being risk evaluation, there is also known a method of collecting present operating states (state data) of steam traps as constituent devices installed in the above-described plant or the like and implementing a maintenance thereof such as replacement of a steam trap based on the state data. Such method is disclosed in Japanese Unexamined Patent Application Publication No. 2010-146186.